For AWS CloudFormation, which stack state refuses UpdateStack calls?

http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks- continueupdaterollback.html

Why are more frequent snapshots or EBS Volumes faster?

volumes or for data backup. If you make periodic snapshots of a volume, the snapshots are incremental so that only the blocks on the device that have changed after your last snapshot are saved in the new snapshot. Even though snapshots are saved incrementally, the snapshot deletion process is designed so that you need to retain only the most recent snapshot in order to restore the volume. http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-creating-snapshot.html

Your serverless architecture using AWS API Gateway, AWS Lambda, and AWS DynamoDB experienced a large increase in traffic to a sustained 400 requests per second, and dramatically increased in failure rates. Your requests, during normal operation, last 500 milliseconds on average. Your DynamoDB table did not exceed 50% of provisioned throughput, and Table primary keys are designed correctly. What is the most likely issue?

you can expect to support 200 requests per second at 100 concurrency. This is less than the 400 requests per second your system now requires. Make a limit increase request via the AWS Support Console. http://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html#limits_lambda

You need to grant a vendor access to your AWS account. They need to be able to read protected messages in a private
S3 bucket at their leisure. They also use AWS. What is the best way to accomplish this?

these third parties access to your AWS resources without sharing your AWS security credentials. Instead, the third party can access your AWS resources by assuming a role that you create in your AWS account. http://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_common-scenarios_third-party.html

You need to know when you spend $1000 or more on AWS. What’s the easy way for you to see that notification?

limits of the free tier. Billing alarms can help to protect you against unknowingly accruing charges if you inadvertently use a service outside of the free tier or if traffic exceeds your expectations. http://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/free-tier-alarms.html

You are getting a lot of empty receive requests when using Amazon SQS. This is making a lot of unnecessary network load on your instances. What can you do to reduce this load?

messages available to return, in reply to a ReceiveMessage request sent to an Amazon SQS queue. Long polling allows the Amazon SQS service to wait until a message is available in the queue before sending a response. http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-long-polling.html

You need to process long-running jobs once and only once. How might you do this?

other components, and proper configuration prevents duplicate processing. http://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/MessageLifecycle.html

When thinking of DynamoDB, what are true of Global Secondary Key properties?

global secondary index is considered “global” because queries on the index can span all of the data in a table, across all partitions. http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/SecondaryIndexes.html

You need your CI to build AMIs with code pre-installed on the images on every new code push. You need to do this as cheaply as possible. How do you do this?

to create. significant discount (30-45%) compared to On-Demand pricing plus an additional 5% during off-peak times1 for a total of up to 50% savings. https://aws.amazon.com/ec2/spot/pricing/